Industrial Technologies Program

BENEFITS

• Identified potential annual electricity 

savings of more than 11 million kWh

• Found opportunities to reduce energy and 

operating costs by $12.6 million annually

• Identified ways to incorporate lean 

manufacturing and energy management best 

practices to increase productivity, reduce 

inventory, and improve product quality

APPLICATION

Metaldyne’s plant-wide assessment focused on 

improving overall plant efficiency and on reducing 

costs, inventory, and energy use. Best practices 

in energy management, lean manufacturing 

techniques, and emerging technologies were 

evaluated during the assessment.

Metaldyne: Plant-Wide Assessment at Royal Oak Finds 

Opportunities to Improve Manufacturing Efficiency, 

Reduce Energy Use, and Achieve Sigificant Cost Savings 

Summary

Metaldyne recently completed a plant-wide energy assessment at its forging 

facility in Royal Oak, Michigan. The assessment addressed opportunities to 

increase energy efficiency, reduce waste and pollutants, and increase productivity 

by evaluating demand-side energy management, best practices, the use of 

emerging technologies, and potential supply-side improvements. Although the 

assessment focused on the plant’s large energy-using systems and equipment, 

the assessment team also evaluated product inventory and the potential for 

reducing or even eliminating defects, which could also increase the plant’s energy 

efficiency. Lean manufacturing techniques, best practices, and the use of emerging 

technologies that could improve plant efficiency were also considered. If all the 

projects identified during the Royal Oak plant-wide study were implemented, the 

assessment team estimated that total annual energy savings for electricity would 

be more than 11 million kWh. Total annual cost savings were estimated to be 

$12.6 million. 

Public-Private Partnership

The U.S. Department of Energy’s (DOE) Industrial Technologies Program (ITP) 

cosponsored the assessment through a competitive process. DOE promotes plantwide energy-efficiency assessments that will lead to improvements in industrial 

energy efficiency, productivity, and global competitiveness, while reducing waste 

and environmental emissions. In this case, DOE contributed $100,000 of the total 

$200,000 assessment cost.

Plant Description

Metaldyne, Incorporated, is the largest independent forging company in North 

America. Metaldyne’s products include wheel hubs, spindles, rolled rings, and 

transmission and differential gears. Headquartered in the metropolitan Detroit 

area, Metaldyne operates more than 50 facilities throughout the world and has 

nearly 8,500 employees worldwide.

Metaldyne’s Royal Oak, Michigan, operations can produce forged parts in several 

ways using hot-, warm-, and cold-forging processes. Hot-forging processes 

produce high-volume products that include transmission and transfer case 

components, such as gear blanks and bearing races, and wheel-end components, 

such as wheel hubs and spindles. The Royal Oak plant has the world’s largest 

concentration of Hatebur hot-forging machines. These state-of-the-art machines 

forge concentric parts from a full range of carbon and alloy steels at rates from 

70 to 120 pieces per minute. 

Forging Forging BestPractices Plant-Wide Assessment Case Study BestPractices Plant-Wide Assessment Case Study
Industrial Technologies Program

The plant is also capable of warm-forging parts that require a greater degree of precision than can be 

achieved with hot-forging. Warm-forging is ideal for producing complex shapes with refined surface 

finishes, desirable grain flow, and tighter dimensional controls. Warm-forging eliminates the need for 

heat-treat normalizing and allows near-net and net-shaped components to be produced without causing 

structural changes in the raw material. In addition, Metaldyne is now one of the world’s largest coldforging companies. Heat-treating of parts is currently outsourced.

The annual cost of electricity for the Royal Oak plant is about $6 million. The plant spends another 

$40,000 annually for natural gas, plus $500,000 for water and sewer utilities. It operates eight Hatebur 

hot-forging machines, 14 cold-forging presses, a Kurimoto hot-forging press, a warm-forging press, 

three Wagner hot ring rolling machines, and several high-tonnage presses. The Hatebur forging 

machines utilize induction heating. High-power, high-pressure sodium lights provide the plant’s primary 

illumination. Currently, six 150-horsepower (hp) air compressors and two 330-hp air compressors are in use. 

Assessment Approach

Metaldyne and its team conducted a plant-wide energy assessment of the Royal Oak forging facility 

that addressed opportunities to increase energy efficiency, reduce waste and pollutants, and increase 

productivity. Electricity is the plant’s main process-related energy source. Natural gas is used primarily 

for water heating and for heating, ventilation, and air-conditioning (HVAC) systems, and has a negligible 

role in process heating. 

The assessment team evaluated demand-side energy management, best practices, opportunities for 

implementing emerging technologies, and potential supply-side changes. The assessment concentrated 

on the plant’s large energy-using systems and equipment. This large equipment included the solidstate induction heaters for the Hatebur hot-forging machines, the warm-forging press, the hot-forging 

vertical press, the Wagner hot ring rollers, electric motors, material handling equipment, HVAC, and 

lighting. Product inventory and the potential for reducing or eliminating defects were also examined. 

Manufacturing processes were examined for potential lean manufacturing/best practices improvements. 

The assessment team also identified some emerging technologies that could improve manufacturing 

efficiency.

Results and Projects Identified

A team of energy and manufacturing process experts identified 21 assessment recommendations. 

Factoring in process improvements that would result in savings in water and waste production, the Royal 

Oak plant could save more than $12.6 million annually in overall plant energy and operating costs if all 

the assessment recommendations were implemented. The cost of implementing all the projects would be 

approximately $6.5 million. All the recommendations are listed in Table 1. More detailed discussions of 

certain proposed projects follow.

Install air saver nozzles on press machine blowoff lines (AR5)—Several of the presses use a continuous 

stream of compressed air blown through two 3/8-inch open pipes to detach parts from the dies. The 

assessment team recommended installing air-saver, high-thrust nozzles on the air lines to reduce 

compressed air usage. Air-saver nozzles work by entraining ambient air into the flow of compressed air.

Install radiation shields and improve insulation to reduce heat losses from induction heaters (AR9)—

Eight multistage induction heaters are used to preheat the bar stock before forging. The air gaps between 

stages, which allow access for maintenance and temperature measurement, also permit excessive heat 

losses. The assessment team recommended installing an insulated, removable radiation shield to reduce 

heat losses through the air gaps. A quartz window could also be installed to allow the bar stock to be 

inspected visually.

Install a controlled cooling system for parts whose heat treating is currently outsourced (AR10)—

The assessment team recommended that the plant consider options for in-house controlled cooling of 
BestPractices Assessment Case Study

forged parts that are currently being outsourced for heat treating. The options were (1) to use a batchtype cooling system, in which parts are placed in bins and cooled under controlled temperature and time 

conditions immediately after being forged, and (2) to use a batch-type system to control the cooling of 

parts produced from the ring rolling machines, and two continuous (spiral) systems to handle single 

parts produced directly from the Hatebur presses. If cooling bins are used, the batch-type systems should 

feature high-convection recirculating air flow to ensure uniform cooling of all the parts. 

Table 1. Recommendations from the Metaldyne Royal Oak Plant-Wide Assessment

Assessment Recommendation

(AR)

Annual 

Electricity 

Savings (kWh)

Annual Cost 

Savings

Capital Cost

Eliminate excess lighting in warehouse areas (AR1) 115,000 $8,000 $500

Replace 400 W metal halide lamps with 360 W lamps at failure (AR2) 76,000 $5,000 $6,000

Replace standard V-belts with notched V-belts on belt-driven equipment 

(AR3)

32,000 $2,000 $0

Enhance motor management program by using MotorMaster+ software 

for repair/replace analysis (AR4)

40,000 $3,000 $14,000

Install air-saver nozzles on press machine blowoff lines (AR5) 953,000 $64,000 $400

Reconnect compressed air system supply via automation valves in 

primary presses to reduce compressed air use (AR6)

103,000 $7,000 $1,700

Implement maintenance program to identify and repair compressed air 

system leaks (AR7)

347,000 $23,000 $900

Upgrade compressed air system controls (AR8) 576,000 $39,000 $17,800

Install radiation shields and improve insulation to reduce heat losses 

from induction heaters (AR9)

2,678,000 $79,000 $117,000

Install a controlled cooling system for parts whose heat treating is 

currently outsourced (AR10)

NA $6,598,000 $4,750,000

Provide additional baskets or use larger scale basket strainers in scale 

pits to improve mill scale trapping and reduce pit cleaning frequency 

(AR11)

NA $99,000 $85,500

Install water meters on blowdown lines from cooling towers to document 

water loss from evaporation and apply for sewer charge exemption for 

water not sent to sewer (AR12)

NA $116,000 $6,500

Install new groundwater supply system to reduce consumption of city 

water (AR13)

NA $272,000 $180,000

Reduce change-over time for press retooling (AR14) 862,000 $43,000 $10,000

Reduce product inventory (AR15) NA $1,800,000* $25,000

Establish a “pull scheduling” system (AR16) NA $720,000 $10,000

Improve product quality and reduce rework (AR17) NA $180,000 $20,000

Increase machine tool durability (AR18) NA $710,000 $60,000

Increase punch and die life by applying lubricating coatings (AR19) 4,478,000 $3,500,000 $1,200,000

Implement a “closed loop” procurement/disposal system to reduce cost 

of tool steel material (AR20)

NA $27,000 $10,000

Employ alternative forging tool design and selection (AR21) 1,260,000 $84,000 $20,000

Totals 11,520,000 $12,579,000 $6,535,300

*One-time savings only; not included in total savings.
Industrial Technologies Program

Printed with a renewable-source ink on paper containing at least 50% wastepaper, including 20% postconsumer waste

BestPractices is part of the Industrial Technologies 

Program, and it supports the Industries of the 

Future strategy. This strategy helps the country’s 

most energy-intensive industries improve their 

competitiveness. BestPractices brings together 

emerging technologies and energy-management 

best practices to help companies begin improving 

energy efficiency, environmental performance, 

and productivity right now.

BestPractices emphasizes plant systems, where 

significant efficiency improvements and savings 

can be achieved. Industry gains easy access 

to near-term and long-term solutions for improving 

the performance of motor, steam, compressed 

air, and process heating systems. In addition, 

the Industrial Assessment Centers provide 

comprehensive industrial energy evaluations 

to small- and medium-size manufacturers.

A Strong Energy Portfolio 

for a Strong America

Energy efficiency and clean, renewable 

energy will mean a stronger economy, a 

cleaner environment, and greater energy

independence for America. Working with 

a wide array of state, community, industry, 

and university partners, the U.S. Department 

of Energy’s Office of Energy Efficiency 

and Renewable Energy invests in a diverse 

portfolio of energy technologies.

DOE/GO-102005-2119

May 2005

PROJECT PARTNERS

Energy Information Systems

Edison Material Technology Center

Azimuth

AT&T

BuyCastings.com

Dayton, Ohio

E3M

Washington, DC

University of Michigan

Ann Arbor, Michigan

Ohio State University

Columbus, Ohio

Mid-West Building Diagnostics

Xenia, Ohio

International Center for Water Resources 

Management, Central State University

Wilberforce, Ohio

FOR ADDITIONAL INFORMATION, PLEASE CONTACT:

EERE Information Center

1-877-EERE-INF

(1-877-337-3463)

www.eere.energy.gov

Visit our home page at

www.eere.energy.gov/industry

Industrial Technologies Program

Energy Efficiency and Renewable Energy

U.S. Department of Energy

Washington, DC 20585-0121

Reduce change-over time for press retooling (AR14)—Current press changeover times for die replacement are longer than necessary; this results in increased 

machine downtime and wasted electricity because the induction heaters remain hot 

while the machine is idle. The assessment team recommended a list of actions to 

reduce change-over time, including improving personnel training and procedures, 

upgrading the tool kit, and using automatic locators for dies.

Reduce product inventory (AR15)—The current average stored inventory is one 

month’s production of finished product, which the assessment team considered to 

be excessive. The team recommended that the plant reduce its product inventory 

by 50% by taking the following actions:

• Producing smaller lot sizes of product 

• Using controlled supermarkets1 for each product type

• Setting minimum and maximum inventory levels for each product type.

Savings would result from reductions in inventory carrying costs, i.e., those 

associated with keeping inventory. These include capital costs, taxes, insurance, 

handling costs, warehouse costs, and damaged inventory.

Establish a “pull scheduling” system (AR16)—The goal of lean manufacturing 

is to minimize or eliminate non-value-added steps in the process across the entire 

product supply, production, and customer delivery cycle. The “pull scheduling” 

approach ensures that upstream manufacturing activities are linked and controlled 

by the activities of the next downstream operation. The downstream operation 

physically sends distinct visual or electronic signals2 to the last upstream operation, 

directing that operation to respond to its needs for a product or service. This 

approach is thus essentially process-driven.

Improve product quality and reduce rework (AR17)—Currently, product 

inventory is excessive and parts are stored longer than necessary. As a result, 

inventory stored outside can experience surface degradation caused by rain. The 

assessment team recommended reducing product inventory and improving material 

flow through the plant. These measures would reduce storage time and associated 

rework on degraded material.

Increase machine tool durability (AR18)—A new technology that can increase 

the life of stamping tools and improve the finish of stamped parts involves the 

application of hard coatings made of thin-film nitride or carbide-based ceramics. 

The assessment team recommended that Metaldyne consider using hard coatings 

on inserts, drills, bits, and other parts to increase the speed of machining 

operations as well as the life of tools. These measures would also reduce press 

downtime and costs associated with punch and die manufacturing.

Increase punch and die life by applying lubricating coatings (AR19)—

The team recommended that the life of the forging tools (punches and dies) be 

increased by maintaining cooler tool surfaces. This could be accomplished by 

reducing the cooling water temperature and by applying a lubricating coating to the 

tool surface. Longer tool life would increase the productivity of the forging presses, 

reduce press downtime, increase throughput, and reduce overall production costs.

These recommendations and others represent more than 20 opportunities for 

Metaldyne to save energy and money at the Royal Oak plant.

1 The “supermarket” concept involves pulling materials from the customers back to production to

optimize product inventory based on customers’ needs.

2 This is known as a “kanban” system in the context of lean manufacturing.